Regular exercise improves mental functioning, and studies show that it reduces the risk of and delays the onset of dementia in people older than 65, she said.

To get started, Eccles-Rotar suggests finding something you love and can stick with through the years, much like Duane has.

“Start slowly, with maybe 10 to 15 minutes, and do it at a moderate level of exertion," Eccles-Rotar said. "Doing short durations of activity multiple times a day can be as effective as doing a whole 30-minute session at once.”

Duane said this summer was his last season on the road.

“I think it's prudent to stop at my age because my balance isn't what it used to be,” he explained.

He set up an exercise bike in an airy room of his home, where he works out daily. A note with the word “exercise” is attached to the bike as a reminder to get moving. Duane acknowledges riding indoors is not as much fun.